Warm, moist air associated with a 994 MB low in the central Gulf of Alaska moved over the Northern Panhandle on the night of Tuesday October 30th and the morning of Wednesday October 31st. This dumped over a foot of new snowfall over Skagway and the Klondike Highway to White Pass by the morning of Halloween Day.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS AJK wrote it up.
Warm, moist air associated with a 994 MB low in the central Gulf of Alaska moved over the Northern Panhandle on the night of Tuesday October 30th and the morning of Wednesday October 31st. This dumped over a foot of new snowfall over Skagway and the Klondike Highway to White Pass by the morning of Halloween Day. No reports of damage or accidents so far. The upper Chilkat Highway also got over a foot of new snow.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Juneau, AK wrote its last area forecast discussion before the first event at Oct 30, 4:25 AM AKST, 7 hours 35 minutes earlier.
SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
525 AM AKDT TUE OCT 30 2012
.SHORT TERM...LOW PRESSURE IS SLOWLY DEEPENING OVER THE NW GULF
AND WILL DRIFT TO THE NORTH-CENTRAL GULF BY THIS EVENING. A TROF
TO THE SE OF THE LOW WILL MOVE TO THE OUTER COAST THIS AFTERNOON.
A COLD FRONT WILL DEVELOP OVER THE WESTERN GULF THIS MORNING AND
MOVE INTO THE EASTERN GULF BY THIS EVENING. THE FRONT SHOULD MOVE
THRU THE PAYA AREA BY LATE EVENING. USED A BLEND OF THE 00Z ECMWF
AND 06Z NAM FOR THE SHORT TERM PERIOD.
MAIN FORECAST ISSUES WILL BE PRECIP POTENTIAL...PTYPE...AND SNOW
AMOUNTS. MUCH OF THE PRECIP WILL BE FOCUSED ALONG THE TROF
MOVING TO THE COAST AND COLD FRONT MOVING IN...WITH OTHER PRECIP
FROM OVERRUNNING THE ARCTIC AIRMASS OVER THE NRN AREA. WENT WITH
MOSTLY CAT POPS NW OF THE FREDERICK SOUND AREA...WITH THE PRECIP
THREAT DIMINISHING QUICKLY TO THE SE...WITH THE FAR SERN AREA
REMAINING DRY THRU TONIGHT.
AS FOR PTYPE AND AMOUNTS...THE AIRMASS OVER THE GULF IS FAIRLY
MILD WITH TEMPS WELL INTO THE 40S. THIS WILL GRADUALLY ERODE THE
ARCTIC AIRMASS OVER THE NRN AREAS IN A DEEP LAYER ONSHORE FLOW.
THE PAYA AREA HAS ALREADY SEEN RAIN MIX IN WITH LOWER LEVEL FLOW
BECOMING MORE SELY EARLY THIS MORNING. THINK A TRANSITION FROM
SNOW TO RAIN SHOULD OCCUR ALONG THE OUTER COAST LATER THIS
MORNING AND EARLY AFTERNOON...WITH THE PAOH/PAGS/PAGN AREAS
SEEING SNOW BECOMING MIXED WITH RAIN THIS AFTERNOON AND EVENING
BEFORE BECOMING MAINLY RAIN. THE PAJN AREA SHOULD SEE SNOW TODAY
WITH SOME RAIN POSSIBLY MIXING IN TONIGHT. PAHN AND PAGY AREAS
SHOULD REMAIN SNOW THROUGH TONIGHT ALTHOUGH IT MAY BECOME FAIRLY
WET NEAR SEA LEVEL TONIGHT.
AS FOR SNOW AMOUNTS...LOOKS LIKE A FAIRLY GOOD SNOW SET UP FOR
THE PAHN ZONE AND UPPER ELEVATIONS OF THE PAGY ZONE. LOWER LEVEL
FLOW WILL HAVE SOME ELY COMPONENT WHICH WILL BE UPSLOPE FOR THE
CHILKAT VALLEY. HAVE CONTINUED THE WINTER WEATHER ADVY THERE THRU
TONIGHT FOR A TOTAL OF 6 TO 10 INCHES OF SNOW. FOR THE PAGY
ZONE...FLOW WILL VEER TO SWLY ALOFT AROUND 2000-3000 FEET...WHICH
IS A GOOD UPSLOPE FOR THE HIGHER END OF THE KLONDIKE HIGHWAY.
WENT WITH A WINTER STORM WARNING FOR ABOVE 1500 FEET IN THE PAGY
ZONE FOR THIS AFTERNOON AND TONIGHT FOR 8 TO 12 INCHES OF SNOW.
LOWER ELEVATIONS SHOULD SEE LESS THAN ADVY SNOWFALL NEAR PAGY.
ELSEWHERE OVER THE N...GENERALLY 1 TO 5 INCHES OF SNOW IS LIKELY
THRU TONIGHT...WITH THE LOWER AMOUNTS WHERE RAIN BEGINS TO MIX IN
EARLIER. STILL...IT SHOULD BE THE FIRST ACCUMULATING SNOW FOR
MUCH OF THE AREA. DECIDED TO LET THE SPS EXPIRE THIS MORNING AS
THE EVENT HAS BEEN FAIRLY WELL ADVERTISED AND IS NOW IN THE NEAR
TERM.
&&
.LONG TERM...SNOW AND RAIN IN THE NORTHERN PANHANDLE WILL BE
DIMINISHING WED AS THE PARENT LOW IN THE NORTHERN GULF STARTS TO
SLIP SW AND WEAKEN. THIS IS IN RESPONSE TO THE UPPER LEVEL TROUGH
THAT SPAWNED IT STARTING TO ELONGATE TO THE SW TAKING ITS UPPER
LEVEL SUPPORT WITH IT. RAIN SHOWERS OVER MOST OF THE AREA,
POSSIBLY MIXING WITH SNOW IN A FEW PLACES IN THE NORTHERN
PANHANDLE, WILL CONTINUE AROUND THE AREA THROUGH EARLY THURS AS
STRONG SW FLOW CONTINUES IN THE UPPER LEVELS. HIGHEST
ACCUMULATIONS WILL BE ON WED. THE PANHANDLE WILL DRY OUT BRIEFLY
ON THURS AFTERNOON AND NIGHT AS A WEAK RIDGE BUILDS INTO THE
AREA.
BY THURS NIGHT A NEW STORM WILL BE DEVELOPING IN THE NORTHERN
PACIFIC. THIS SOUTHERN STREAM STORM WILL GET A BOOST FROM THE
SAME UPPER TROUGH THAT JUST ABANDON THE NORTHERN GULF LOW. BY
EARLY FRI IT WILL HAVE STRENGTHENED TO 952 MB IN THE SW GULF AND
WILL BE SENDING A RATHER POTENT FRONT INTO THE PANHANDLE. FRI
INTO FRI NIGHT IS LOOKING TO BE RATHER WET AND WINDY FOR MOST
AREAS. SOUTHERN PANHANDLE LOOKS LIKE IT WILL BE ESPECIALLY WINDY
AS THE GFS IS SUGGESTING A 75 KT LOW LEVEL JET SLAMMING INTO THAT
AREA. THIS MAY BRING SOME WARNING LEVEL WINDS TO THAT AREA ON
FRIDAY. OTHER AREAS WILL BE SEEING GUSTY WINDS FRIDAY AND GALES
WILL BE BLOWING IN THE GULF AND INNER CHANNEL AREAS. AS FOR
PRECIP MOST PLACES WILL SEE IT AS RAIN SINCE THE S TO SE FLOW
THAT WAS ACCOMPANIED THE NORTHERN GULF LOW MID WEEK AND THE SE
FLOW AHEAD OF THE STRONG FRONT HAVE DONE A GOOD JOB OF GETTING
RID OF THE COLD AIR THAT WAS IN THE INNER CHANNELS. THE ONLY AREA
THAT STILL MAY SEE SOME SNOW IS WHITE PASS. BUT EVEN THEN IT
MIGHT BE A WET SLUSHY ACCUMULATION IN THE SOUTHERN FLOW.
WINDY CONDITIONS CONTINUE INTO SAT AS THE SECOND WRAP OF THE
SYSTEM SLAMS INTO THE CENTRAL OR NORTHERN OUTER COAST BRINGING
MORE WIND, RAIN, AND HIGH SEAS TO THE AREA. CONDITIONS QUIET DOWN
BY SUNDAY AND MONDAY AS THE REMNANT LOW CONTINUES TO SPIN IN THE
NORTHERN GULF SENDING SHOWERS INTO THE PANHANDLE FOR THE LATE
WEEKEND.
LONG RANGE MODELS IN FAIR AGREEMENT FOR THE FIRST HALF OF THE
PERIOD. MAIN DIFFERENCES START TO COME IN WITH THE NEXT STRONG
STORM LATE WEEK. OPERATIONAL ECMWF AND GFS WERE EARLIER
SUGGESTING A SLIGHTLY FASTER PROGRESSION TO THE LOW THEN PREVIOUS
MODELS WERE SUGGESTING BUT THE NEW 6Z GFS HAS SLOWED THE LOW DOWN
AGAIN. SOME TRACK ISSUES ALSO PRESENT AS GFS WANTS TO TAKE THE
LOW FURTHER EAST THEN THE ECMWF AND CONSEQUENTLY BRING THE SECOND
WRAP FURTHER EAST AS WELL ON SAT. DECIDED ON A BLEND OF THE NAM
WITH SOME ECMWF FOR MID RANGE GRIDS AND THEN TRANSITIONED TO HPC
IN THE EXTENDED PERIOD WITH ITS INCORPORATION OF THE MORE STABLE
ENSEMBLE MEANS. FORECAST CONFIDENCE IS A LITTLE ABOVE AVERAGE.
.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...WINTER WEATHER ADVISORY FROM 10 AM THIS MORNING TO 7 AM AKDT
WEDNESDAY FOR AKZ019.
WINTER STORM WARNING FROM 1 PM THIS AFTERNOON TO 7 AM AKDT
WEDNESDAY FOR AKZ018.
MARINE...GALE WARNING FOR PKZ051.
SMALL CRAFT ADVISORY FOR PKZ011-021-022-031>034-042-043-052.
SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ041.
&&
RWT/EAL1 winter storm, 1 heavy snow. Local standard time, as filed.
Several measurements of heavy snow between 1.0 to 1.5 FT were reported from all elevations around Skagway and the Klondike Highway on the night of October 30th to around noon on Halloween Day.
Haines Customs measured 14 inches of new snow on the morning of October 31st.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Alaska in 2012Every state in 2012This day in weather historyWarnings in Alaska, October 2012
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 414443, 414444.